Web tester documentation

Fetching a page

Testing classes is all very well, but PHP is predominately a language for creating functionality within web pages. How do we test the front end presentation role of our PHP applications? Well the web pages are just text, so we should be able to examine them just like any other test data.

This leads to a tricky issue. If we test at too low a level, testing for matching tags in the page with pattern matching for example, our tests will be brittle. The slightest change in layout could break a large number of tests. If we test at too high a level, say using mock versions of a template engine, then we lose the ability to automate some classes of test. For example, the interaction of forms and navigation will have to be tested manually. These types of test are extremely repetitive and error prone.

Testing page content

To confirm that the page we think we are on is actually the page we are on, we need to verify the page content.

class TestOfLastcraft extends WebTestCase {
    
    function testHomepage() {
        $this->get('http://www.lastcraft.com/');
        $this->assertText('Why the last craft');
    }
}

Here is the list of possible content assertions...

So now we could instead test against the title tag with...

$this->assertTitle('The Last Craft? Web developer tutorials on PHP, Extreme programming and Object Oriented development');

$this->assertTitle(new PatternExpectation('/The Last Craft/'));

$this->assertMime(array('text/plain', 'text/html'));

class TestOfLastcraft extends WebTestCase {
    
    function testRedirects() {
        $this->get('http://www.lastcraft.com/test/redirect.php');
        $this->assertResponse(200);
    }
}

class TestOfLastcraft extends WebTestCase {
    
    function testHomepage() {
        $this->setMaximumRedirects(0);
        $this->get('http://www.lastcraft.com/test/redirect.php');
        $this->assertResponse(200);
    }
}

Web site tests
1) Expecting response in [200] got [302]
    in testhomepage
    in testoflastcraft
    in lastcraft_test.php
FAILURES!!!
Test cases run: 1/1, Failures: 1, Exceptions: 0

class TestOfLastcraft extends WebTestCase {
    
    function testHomepage() {
        $this->setMaximumRedirects(0);
        $this->get('http://www.lastcraft.com/test/redirect.php');
        $this->assertResponse(array(301, 302, 303, 307));
    }
}

Navigating a web site

Users don't often navigate sites by typing in URLs, but by clicking links and buttons. Here we confirm that the contact details can be reached from the home page...

class TestOfLastcraft extends WebTestCase {
    ...
    function testContact() {
        $this->get('http://www.lastcraft.com/');
        $this->clickLink('About');
        $this->assertTitle(new PatternExpectation('/About Last Craft/'));
    }
}

If the target is a button rather than an anchor tag, then clickSubmit() can be used with the button title...

$this->clickSubmit('Go!');

$this->click('Go!');

The list of navigation methods is...

The parameters in the get(), post() or head() methods are optional. The HTTP HEAD fetch does not change the browser context, only loads cookies. This can be useful for when an image or stylesheet sets a cookie for crafty robot blocking.

The retry(), back() and forward() commands work as they would on your web browser. They use the history to retry pages. This can be handy for checking the effect of hitting the back button on your forms.

The frame methods need a little explanation. By default a framed page is treated just like any other. Content will be searced for throughout the entire frameset, so clicking a link will work no matter which frame the anchor tag is in. You can override this behaviour by focusing on a single frame. If you do that, all searches and actions will apply to that frame alone, such as authentication and retries. If a link or button is not in a focused frame then it cannot be clicked.

Modifying the request

Although SimpleTest does not have the goal of testing networking problems, it does include some methods to modify and debug the requests it makes. Here is another method list...